The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > General Truck Forums > Engine & Drivetrain > LSx Swaps

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 06-23-2024, 08:36 AM   #1
A1971Blazer
Senior Member
 
A1971Blazer's Avatar
 
Join Date: Nov 2013
Location: East Tennessee
Posts: 2,188
Fan issue with AC trinary switch

'67 C10 with '02 LS1
I'm running the Entropy LS swap radiator with dual fans.

Fan 1 is wired to the PCM only, it triggers the relay at 195º, it works perfectly.
Fan 2 is also wired to the PCM to trigger at 205º and it's also wired to the trinary switch and connected to the same trigger (ground).

The fan will come on via the trinary switch or the PCM or both ( I assume)
I'm getting a code P0481 (fan 2) when I have the AC on and the PCM triggers the fan 2 relay. I did find a loose connector in my load center for the fan 2 relay but I fixed that.

I'm wondering if the trinary switch and the PCM fan trigger being wired together is causing the issue, and what is the best/easiest way to correct it?
__________________
1967 C10 Step side
1968 C10 Step side
1970 Chevrolet K/5 Blazer
1972 Chevrolet K/5 Blazer
.............
A1971Blazer is offline   Reply With Quote
Old 06-24-2024, 07:05 AM   #2
A1971Blazer
Senior Member
 
A1971Blazer's Avatar
 
Join Date: Nov 2013
Location: East Tennessee
Posts: 2,188
Re: Fan issue with AC trinary switch

I rewired the fans and separated the PCM trigger and the trinary switch ground triggers

Name:  fan wiring 1.jpg
Views: 163
Size:  18.2 KB
__________________
1967 C10 Step side
1968 C10 Step side
1970 Chevrolet K/5 Blazer
1972 Chevrolet K/5 Blazer
.............

Last edited by A1971Blazer; 07-01-2024 at 05:02 PM.
A1971Blazer is offline   Reply With Quote
Old 06-24-2024, 07:05 AM   #3
v30crewcab
Registered User
 
v30crewcab's Avatar
 
Join Date: Apr 2012
Location: Chatt Tn
Posts: 978
Re: Fan issue with AC trinary switch

computers don't like additional stuff. you need to wire it thru a relay were its either or, not wired together.
__________________
88 military v30 crewcab shortbed 5.9 cummins, nv4500, 205
86 k30, 89 diesel burb, 76 gmc pathfinder
71 longbed 5.3 4l80
http://67-72chevytrucks.com/vboard/s...d.php?t=522535
v30crewcab is offline   Reply With Quote
Old 06-24-2024, 07:08 AM   #4
A1971Blazer
Senior Member
 
A1971Blazer's Avatar
 
Join Date: Nov 2013
Location: East Tennessee
Posts: 2,188
Re: Fan issue with AC trinary switch

Quote:
Originally Posted by v30crewcab View Post
computers don't like additional stuff. you need to wire it thru a relay were its either or, not wired together.
thanks....see post#2
__________________
1967 C10 Step side
1968 C10 Step side
1970 Chevrolet K/5 Blazer
1972 Chevrolet K/5 Blazer
.............
A1971Blazer is offline   Reply With Quote
Old 06-24-2024, 09:58 PM   #5
v30crewcab
Registered User
 
v30crewcab's Avatar
 
Join Date: Apr 2012
Location: Chatt Tn
Posts: 978
Re: Fan issue with AC trinary switch

cool, thats how I was thinking just wasn't sure how to explain it!
__________________
88 military v30 crewcab shortbed 5.9 cummins, nv4500, 205
86 k30, 89 diesel burb, 76 gmc pathfinder
71 longbed 5.3 4l80
http://67-72chevytrucks.com/vboard/s...d.php?t=522535
v30crewcab is offline   Reply With Quote
Old 07-07-2024, 09:26 PM   #6
87chevy.com
BMW & ASE Master Certified
 
87chevy.com's Avatar
 
Join Date: Feb 2004
Location: Houston, Texas
Posts: 1,266
Re: Fan issue with AC trinary switch

id say best bet, wire it like OE and never look back.

a/c wiring



https://ls1tech.com/forums/attachmen...ingfansbu6.gif

fans


https://ls1tech.com/forums/attachmen...ingfansbu6.gif
so when wired like oem, both fans run together at 1/2 speed (because both motors are powered by 1 relay). and when high speed is requested due to a/c on signal or coolant temp, both fan run at full speed since its running 1 fan on each relay seperatly.

clint
__________________
1987 Silverado - L83 5.3 w/ 6L80e ,A/C,P/W,P/L,TILT, HID projectors, Wilwood C-10 Pro Spindles w/ 2018 silverado front brakes & C-5 Corvette Rear Disc Brakes
1999 BMW 528i - 5.7 LS1 w/ 4l60e, Ford 8.8 IRS w31 spline posi & FX-r projector retrofit

New project: 2006 BMW x5 6cyl AWD to L83 6l80e 4wd to 2WD / RWD

A poor man buy's it twice

finally got my domain name back, 87chevy.com.... site rework in progress
87chevy.com is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 04:48 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com